An air bath is one of the methods to train a body and to prevent illness by exposing the body in a specific air environment and by using physical properties and chemical components of air. The air bath equally provides favorable influence on both conditioning of blood circulation and human tissues and organs. It is said that trace elements in air, inorganic salts, oxygen and the like can enhance activity and an immune function of an organic body, and increase in oxygen content in the blood by absorbing fresh air is highly effective for assisting protection of a cardiopulmonary function.
For training a body by employing the air bath, a stimulus caused by difference between temperature of air (air temperature) and a body temperature is mainly used. Thermal change of air temperature activates a thermoregulation function of body, cerebral cortex, and reflex center of vasomotion, and favorably trains the body. For example, a stimulus caused by cold air constricts blood vessels in the body surface and allows blood to flow in a direction of internal organs. On the contrary, a stimulus caused by warm air dilates blood vessels in the body surface and allows blood to flow in a direction of the body surface. In addition, the air bath is expected to provide stress relaxation for not only humans but also animals.
One of the inventors of the present invention has offered an optimal pressure control apparatus and a method for controlling pressure of the apparatus in order to take the air bath using a stimulus caused by temperature difference (Patent Document 1).